Army's 'Super Engine' Would Streamline Fuel Use

The US military is looking to bolster fuel efficiency by creating a so-called "super engine" that runs on one type of fuel and can power a number of vehicles, including ground transport, generators, and small unmanned aerial vehicles (UAVs).

The US Army Research Laboratory (ARL) has been working on this task since the Department of Defense established a Single Fuel Forward policy in the late 1980s. The policy supported the use of a kerosene-based fuel called JP-8 to reduce the logistical burden involved in transporting and supplying different sources of energy to vehicles in combat areas and other locations, according to the Army.

Over the years, researchers have faced compatibility issues between the different engines, the Army said. Its research began with the use of turbine engines, but has now moved on to exploring the use of combustion engines.

Two international contractors inspect a sample of JP-8 fuel in Kuwait in 2010. The Army hopes to use the fuel as the basis for a "super engine" that can power a number of ground and air vehicles, as well as generators using this fuel. (Source: US Army Sgt. David Reardon, 1st Sustainment Brigade Public Affairs, US Army)

Incompatibility issues are chiefly in engine lubrication, large variation in Cetane numbers -- or the measurement between the start of fuel injection and the start of engine ignition or combustion -- and the fact that none of the engines that use JP-8 are designed and calibrated for the fuel, said Dr. Chol-Bum Kweon, acting team lead of the Engines Team of ARL’s Vehicle Technology Directorate, in a press release.

The main reason for these issues is that there is not enough information readily available about the specific combustion characteristics associated with the use of JP-8 in intermittent combustion engines, Kweon added.

The opening of a new lab this summer, the ARL Combustion Research Laboratory, should help speed up this research, particularly with respect to fuel spray and combustion, two critical areas key to the creation of a JP-8 engine. According to Kweon:

ARL’s Combustion Research Laboratory is a state-of-the-art, high- temperature and high-pressure combustion chamber that contains a combination of high temperatures up to 1,000 Kelvin and high pressure up to 150 bar. These metrics can simulate the operations of a real engine, minus its fluid motion aspect. The lab gives scientists a realistic proving ground for, in particular, uninterrupted spray and combustion processes that allow for the study necessary to create a JP-8 fuel-injection engine.

In addition to supporting the development of a JP-8 engine, researchers will also use the lab to test the performance of heavy fuel injection systems for diesel, bio, and synthetic fuels, as well as assess the impact of fuel properties on spray and combustion processes on engine performance and efficiency.

Researchers also can determine the impact of older fuel-injection systems on engine performance and fuel efficiency, especially for the Army’s ground vehicles, and evaluate various iterations of JP-8 fuels being developed throughout the DoD, Kweon said, going on to explain: "This laboratory has a unique capability to assess the various JP-8 surrogate fuels and to compare the results with the combustion mechanisms developed by various universities and government lab or atories."

All of this work to develop a universal combustion mechanism for JP-8 supports a trend across the US military to create more energy efficiency, and find alternative and better sources and uses of fuel. Other efforts include the Navy’s development of a biofuel made of seawater; the Air Force’s use of vortex surfing -- or flying planes in tight formation so they can draft off each other -- to conserve fuel; as well as other Army projects such as developing more fuel-efficient electricity generators.

56ml, I was not trying to denigrate government research, or DARPA, in general. On the other hand, we hear more about this than we do about privately funded or univeristy research, for obvious reasons. Thus, we have more to "comment" on. I have worked on DARPA funded projects, Atomic Energy Commission funded projects (long ago) and corporate R&D funded projects. The DARPA projects were mainly about things that had not been done yet, and were perhaps premature. That's appropriate for such an agency.

I direct you to eafpres' comment. Is this really a research project?

bob from maine also has a very good point. Our military services are really wonderful organizations in many ways, but there are still some major bureuacratic issues that need to be dealt with before some major effeciencies can be realized. Just as an example, the Army, under criticism for its choice of cammo for uniforms, talked about adopting the Marine uniform patterns. The Marines shot back, no you can't, that's ours. Of course it is not theirs. Those patterns are property of the US Government (meaning us). I saw a lot of this, along with some major sharing, when I worked in the aerospace business.

Interesting, Bob, I didn't know that bit of history about the Army. It actually seems like something like that is a more fuel efficient and practical option that creating some kind of super fuel that is specialized. And streamlining across all military branches seems like a no brainer, even though as you point out it's just the opposite!

Good points, TJ. Personally I think local is the way to go, and am more interested in the military's use of alternative sources of fuel and setting up local solar and wind arrays than in this type of investment. There are definitely some other military efforts in terms of energy sourcing and consumption that are more appealing both financially and ecologically.

I hear what you're saying, naperlou, and it's completely true. If you want innovation, you really have to look at private business. I wrote about the government for another publication for about two years and in that time I felt like I was writing the same story over and over...the government was pondering this or that legislation and really meant to address it imminently, but it never happened. I do think, though, that DARPA is an exception, but they work with the private sector (ie, Boston Dynamics) to do a lot of their robotics innovations.

Should this come to fruition, the army has added a huge burden to its logistical tail. Instead of being able to source fuel locally, the army will have to bring it with them from much further away. The army claims switching would reduce its logistical burden, but that statement sounds like smoke and mirrors.

JP8 seems only to be used by the US military and some allies. However, this article:

My Ph.D. professor and many of his student are largely responsible for the multiple advances that made commercially viable LED possible today. We did research at the university and published papers, everyone of which was supported in part by the predecessor of DARPA. To denigrate government sponsored R&D is overreaching in my opinion.

In my nearly 40 year career outside of the light-emitting field, I have worked in two prestigeous Fortune 50 research labs. Most projects don't pan out. To the outsider, it would be called waste and abuse if those government work. For corporations, everything is just fine to the same people. Research is hard. If it were easy, it would already have been done. Few people are as intelligent or knowledgable as those who read these blogs and comment. If the whole population were as smart as we are, we would just be average Joes. In this economy, we would just be scraping by, not enjoying our comfortable life.

DARPA does some good work, naperlou, but I generally agree with you. Too often, government is behind the curve. This is often true in electronics, where the best graphics processors are avilable for games, not defense.

At the end of WWII the Army had a multi-fuel-engine that they put into most of their heavy duty trucks. They ran best on diesel but as the instruction manual said "If it'll burn, it'll run in this engine". The engines weren't very fuel efficient but no matter where in the world you ended-up, you could always find fuel. Navy ships that used boilers burned bunker-C, what's left over after just about everything else had been refined out of a barrel of oil. They also burned crude oil. Naval aircraft have been using a different Jet Fuel than the Air-Force for years. As engines get more efficient and specialized, the fuel required becomes more specialized. Research on fuels by the military is nothing new, but it's a sure bet that if the Army is able to derive a single-fuel approach, the Air-Force, Navy and Marines will find another method.

Wow, let's just reinvent combustion research! Seriously, don't you think that, say, taking each of the engine/vehicle platforms the military desires to use JP8 in, giving them to good engineering teams, and telling them "figure this out" would lead to answers quicker than studying vaporization in combustion chambers? I'm a scientist at heart, then a technologist, so I'm biased towards R&D. But this is over the top.

Elizabeth, one fact that you mention in your article is interesting and all too familiar to me. The fact that the single fuel policy (which is a good idea) was originally put forward in the 1980s. Consider what your article says. They are just now getting around to doing some of the basic research. This is just sad. I did a lot of government and corporate funded research over the years, and it often seems that the government is generally behind the curve. Remember, all of the systems they used are made by industrial concerns, not by the government. I remember when that decision was made in earnest. I remember because my father worked at an Army research lab. He was lamenting that they were contracting everything out.

This situation is also interesting in relation to autonomous vehicle research. The government, again for the military, has been looking at this since at least the 1980s. Who is really doing it now, Google. The whole situation is that the government sometimes starts to work on things when they are really are not feasible. I saw a lot of that. That is why a lot of the talk about DARPA in Design News amuses me, sometimes. It might be much more interesting to see what is being done in Japan in robotics. They are doing some really innovative stuff and it is not in the military realm.

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